Hazelnut and White Chocolate Roulade

Generally I don’t mind messing about with recipes even if they're classics, but I really don't want to mess around too much with the sponge part of a roulade – that's just asking for trouble. So this is a classic roulade sponge method. Not original, perhaps, but it works and that'll do for me.

I've combined hazelnuts and white chocolate in cakes before in this blog, but it's a combination that I enjoy a lot and, for some reason, I'm slightly hooked on hazelnuts at the moment.

For the sponge:
     70 g caster sugar, plus a bit more for sprinkling
     3 eggs
     45 g ground hazelnuts (make sure there are no lumps)
     20 g plain flour, sieved
For the filling:
     70 g unsalted butter
     70 g white chocolate
     100 g icing sugar, sieved
     70 g hazelnut butter
     40 g mascarpone

Line a 20 x 30 cm Swiss roll tin with non-stick baking paper and then rub some butter over the paper to make sure that nothing could possibly stick to it. (I think the difficulty with this sponge is the risk of sticking and not the rolling). Preheat the oven to 180°C.

Whisk the eggs and caster sugar together thoroughly until they’re very pale and the whisk leaves a definite trail through the mixture. Fold in the hazelnuts and the flour. Pour the mixture into the prepared tin and spread it as evenly as possible.

Place in the oven for 15 – 18 minutes until the sponge feels slightly springy, though still soft. (It may rise a little more than you expect, but it will tend to fall back on cooling.)

While the sponge is in the oven, cut another sheet of baking paper a little larger than the Swiss roll tin, lay it over a damp tea towel (you may need to weigh down the corners) and sprinkle it with caster sugar. As soon as the sponge is out of the oven, turn it out onto the sugared baking paper and carefully remove the lining paper. Take a deep breath and roll the sponge up (from the narrowest edge) so that the sugared paper is wrapped up inside. Carefully lift the roll onto a cooling rack. Make sure that the tea towel is only very slightly damp and lay it over the rolled sponge. Remove the tea towel after 5 minutes or so but leave the sponge alone until it feels completely cold.

To make the filling, melt together the butter and chocolate in a bowl over simmering water. Remove from the heat and stir in the icing sugar and the hazelnut butter. Allow the filling to cool completely, then stir in the mascarpone. Put the filling in the fridge until you need it.

Unroll the cold sponge and discard the baking paper. Tidy up any ragged edges with a sharp knife (unless you’re feeling very relaxed about the way it looks) and spread the filling evenly over the sponge. Roll the roulade up again being careful not to squidge the filling too much.

Dust the roulade with icing sugar and, if you’re not eating it at once, store in the fridge.